Vibration control apparatus for elevator

ABSTRACT

A passenger car of an elevator is transversely vibrated when it is hoisted up or down due to curves in guide rails and level differences at joints of the guide rails. An elevator vibration control apparatus of this invention employs a vibration or displacement sensor attached to a passenger car chamber to detect such transverse vibration of the passenger car. A controller calculates an operation quantity of an actuator to cancel the detected vibration of the passenger car. According to the calculated operation quantity, a servomotor is driven to displace the passenger car in a direction to cancel the transverse vibration and suppress force applied to the passenger car. As a result, the transverse vibration of the passenger car is reduced, and comfortableness of riding in the passenger car is improved.

TECHNICAL FIELD

This invention relates to a vibration control apparatus for an elevator.

BACKGROUND ART

FIG. 16 shows a passenger car of an ordinary elevator that is hoisted upor down along guide rails installed in an elevator passage of ahigh-rise building. The elevator passage 1 has sidewalls along which theguide rails 2 are vertically installed. The passenger car 4 is arrangedbetween the guide rails 2 and is hoisted up or down by hoist cables 3.The passenger car 4 consists of a passenger car frame 5 and a passengercar chamber 6 supported by the passenger car frame 5. Four guide units 7are arranged on the top and bottom of the passenger car frame 5. Asshown in FIG. 17, the guide unit 7 has a guide base 8a fixed to thepassenger car frame 5, a lever 8b having an end rotatably attached tothe guide base 8a, a guide roller 8c rotatably attached to the other endof the lever 8b, a rod 8d having an end fixed to the guide base 8a, anda presser spring 8e arranged between the lever 8b and the rod 8d, tosuppress a displacement of the guide roller 8c. The guide roller 8c isin contact with the side and end faces of the guide rail 2 and rollsalong the guide rail 2.

As shown in FIG. 16, floor support frames 9 are laid on the bottom ofthe passenger car frame 5. Rubber dampers 10 are arranged between thefloor support frames 9 and the bottom of the passenger car chamber 6, tosupport the passenger car chamber 6.

Curves and installation errors in the guide rails 2 and leveldifferences at joints of the guide rails may vibrate the passenger car 4of the conventional elevator. The vibration is transmitted to persons inthe passenger car 4, to make them uncomfortable. The rubber dampers 10absorb such vibration and improve comfortableness in riding theelevator.

The conventional elevator, however, is incapable of completelyeliminating the vibration caused by the guide rails. Generally,vibration due to the guide rails increases as the running speed of theelevator increases. When the speed of the passenger car of the elevatorexceeds a given value, vibration of the passenger car due to the guiderails exceeds an allowable range, to cause uncomfortableness. When thespeed of the passenger car reaches a certain level, a vibrationfrequency due to forcible displacements by the curves in the guide railsagrees with the natural frequency of the passenger car, to cause aresonance. The resonance strongly vibrates the passenger car, todrastically deteriorate comfortableness in the passenger car.

DISCLOSURE OF INVENTION

To solve the problems of the prior art mentioned above, an object ofthis invention is to provide a vibration control apparatus for anelevator, for attenuating vibration of a passenger car of the elevatorby forcibly displacing the passenger car in a direction to attenuate thevibration, or by employing a weight to produce inertial force toattenuate the vibration, thereby improving comfortableness in thepassenger car.

In order to accomplish the object, the invention according to a firstembodiment described in claim 1 provides a vibration control apparatusfor an elevator having guide rails along an elevator passage and guideunits on the top and bottom of a passenger car of the elevator. Theguide unit has a rocking lever, a guide roller rotatably attached to thelever, and a spring to press the guide roller against the guide rail sothat the guide roller may roll along the guide rail. The vibrationcontrol apparatus has an actuator made of a multilayer piezoelectricelement disposed between the spring and guide roller of one of the guideunits, to adjust a transverse displacement of the guide roller, avibration sensor installed on the passenger car, to detect transversevibration acceleration, and a controller for applying a voltage to thepiezoelectric element to displace the actuator in a direction to cancelthe transverse vibration acceleration of the passenger car detected bythe vibration sensor.

The invention according to a second embodiment is based on the vibrationcontrol apparatus of the first embodiment. Each of the top and bottomguide units is provided with the actuator, and the top and bottomactuators are controlled by respective controllers. The vibration sensoris installed on each of the top and bottom of the passenger car, todetect transverse vibration acceleration at the top and bottom of thepassenger car. The vibration sensors provide the controllers withsignals representing detected transverse vibration acceleration.

The invention according to a third embodiment provides a vibrationcontrol apparatus for an elevator having guide rails along an elevatorpassage and guide units on the top and bottom of a passenger car of theelevator. The guide unit has a rocking lever, a guide roller rotatablyattached to the lever, and a spring to press the guide roller againstthe guide rail so that the guide roller may roll along the guide rail.One of the top and bottom of the passenger car is provided with aservomotor, a translation mechanism driven by the servomotor, forconverting rotational motion into linear motion, a weight linearlyhorizontally moved by the translation mechanism, a vibration sensor fordetecting transverse vibration of the passenger car, and a controllerfor driving the servomotor in response to a signal from the vibrationsensor, to linearly horizontally move the weight to produce inertialforce in a direction to cancel the transverse vibration of the passengercar.

The invention according to a fourth embodiment is based on the vibrationcontrol apparatus of the third embodiment. Each of the top and bottom ofthe passenger car is provided with a servomotor, a translation mechanismdriven by the servomotor, for converting rotation motion into linearmotion, a weight linearly horizontally moved by the translationmechanism, a vibration sensor for detecting vibration of the passengercar, and a controller for driving the servomotor in response to a signalfrom the vibration sensor, to linearly horizontally move the weight toproduce inertial force in a direction to cancel the transverse vibrationof the passenger car.

The invention according to fifth embodiment provides a vibration controlapparatus for an elevator having guide rails along an elevator passageand guide units on the top and bottom of a passenger car of theelevator. The guide unit has a rocking lever, a guide roller rotatablyattached to the lever, and a spring to press the guide roller againstthe guide rail so that the guide roller may roll along the guide rail.One of the top and bottom of the passenger car is provided with aweight, a translation mechanism for linearly horizontally move theweight, a servomotor for driving the translation mechanism, adisplacement detector for detecting a transverse displacement of theguide roller, an operation unit for calculating a driving quantity ofthe servomotor according to a signal from the displacement detector, tolet the translation mechanism horizontally move the weight for adistance to attenuate transverse vibration of the passenger car causedby the transverse displacement of the guide roller, and a controller fordriving the servomotor according to the driving quantity calculated bythe operation unit.

The invention according to a sixth embodiment is based on the vibrationcontrol apparatus of the fifth embodiment. Each of the top and bottom ofthe passenger car is provided with a weight, a translation mechanism forlinearly horizontally move the weight, a servomotor for driving thetranslation mechanism, a displacement detector for detecting atransverse displacement of the guide roller, an operation unit forcalculating a driving quantity of the servomotor according to a signalfrom the displacement detector, to let the translation mechanismhorizontally move the weight for a distance to attenuate transversevibration of the passenger car caused by the transverse displacement ofthe guide roller, and a controller for driving the servomotor accordingto the driving quantity calculated by the operation unit.

The invention according to a seventh embodiment is based on thevibration control apparatus of the fifth or sixth embodiment. Twodisplacement detectors are arranged on left and right sides to face eachother. An operation device provides the operation unit with a weightedaverage of displacement signals from the two displacement detectors.

The invention according to an eighth embodiment is based on thevibration control apparatus of any one of the fifth through seventhembodiments. A noncontact-type displacement detector is used to detect adisplacement of the passenger car relative to the guide rail.

The invention according to a ninth embodiment is based on the vibrationcontrol apparatus of any one of the fifth through seventh embodiments. Acontact-type displacement detector is attached to the passenger car, todetect a transverse displacement of the guide roller when the guideroller rolls along the guide rail and provide a signal representing atransverse displacement of the passenger car.

According to the elevator vibration control apparatus of the inventionof the first embodiment, the vibration sensor attached to the passengercar detects transverse vibration of the passenger car caused by curvesin the guide rails or level differences at joints of the guide railswhen the passenger car is hoisted up or down. The controller calculatesa control quantity of the actuator necessary to cancel the vibrationacceleration of the passenger car and provides the actuator with thecalculated control quantity. The multilayer piezoelectric element of theactuator is displaced in response to the control quantity, to displacethe passenger car in a direction to attenuate the transverse vibrationof the passenger car. As a result, force applied to the passenger car issuppressed, the transverse vibration of the passenger car is reduced,and comfortableness of riding in the passenger car is improved.

According to the elevator vibration control apparatus of the secondembodiment, the vibration sensors arranged on the top and bottom of thepassenger car detect transverse vibration at the top and bottom of thepassenger car. The top and bottom controllers calculate controlquantities of the top and bottom actuators necessary to cancel vibrationacceleration at the top and bottom of the passenger car, and provide thetop and bottom actuators with the calculated control quantities. Themultilayer piezoelectric elements of the top and bottom actuators aredisplaced according to the control quantities, to displace the top andbottom of the passenger car in directions to attenuate transversevibration at the top and bottom of the passenger car. As a result, forceapplied to the passenger car is suppressed, the transverse vibration ofthe passenger car is more effectively reduced, and comfortableness ofriding in the passenger car is improved.

According to the elevator vibration control apparatus of the thirdembodiment, the vibration sensor detects transverse vibration of thepassenger car caused by curves in the guide rails or level differencesat joints of the guide rails when the passenger car is hoisted up ordown. The controller processes a signal from the vibration sensor anddrives the servomotor to let the translation mechanism linearlyhorizontally move the weight to produce inertial force in a direction toattenuate the transverse vibration of the passenger car. In this way,the translation mechanism moves the weight to produce the inertial forcethat attenuates the transverse vibration of the passenger car. As aresult, the transverse vibration of the passenger car is reduced, andcomfortableness of riding in the passenger car is improved.

According to the elevator vibration control apparatus of the fourthembodiment, the vibration sensors arranged on the top and bottom of thepassenger car detect transverse vibration at the top and bottom of thepassenger car. The top and bottom controllers process signals from thetop and bottom vibration sensors and drive the servomotors to let thetop and bottom translation mechanisms linearly horizontally move the topand bottom weights to produce inertial force in a direction to attenuatethe transverse vibration at the top and bottom of the passenger car. Inthis way, the inertial force that attenuates the transverse vibration atthe top and bottom of the passenger car is applied to the top and bottomof the passenger car. As a result, the transverse vibration of thepassenger car is more effectively reduced, and comfortableness of ridingin the passenger car is improved.

According to the elevator vibration control apparatus of the fifthembodiment, the displacement detector detects a displacement of thepassenger car due to transverse vibration of the passenger car caused bycurves in the guide rails or level differences at joints of the guiderails when the passenger car is hoisted up or down. According to asignal from the displacement detector, the operation unit calculates adriving quantity of the servomotor to let the translation mechanismhorizontally move the weight for a distance to attenuate the transversevibration of the passenger car due to the transverse displacement of theguide roller. According to the driving quantity calculated by theoperation unit, the controller drives the servomotor. In this way, thetranslation mechanism moves the weight to produce the inertial forcethat attenuates the transverse vibration of the passenger car, and theinertial force is applied to the passenger car. As a result, thetransverse vibration of the passenger car is reduced, andcomfortableness of riding in the passenger car is improved.

According to the elevator vibration control apparatus of the sixthembodiment, the displacement detectors arranged on the top and bottom ofthe passenger car provide signals. The top and bottom operation unitscalculate driving quantities of the top and bottom servomotors to letthe top and bottom translation mechanisms horizontally move the top andbottom weights for a distance to attenuate transverse vibration at thetop and bottom of the passenger car due to transverse displacements ofthe guide rollers. According to the driving quantities calculated by thetop and bottom operations units, the top and bottom controllers drivethe top and bottom servomotors. In this way, the top and bottomtranslation mechanisms move the respective weights to produce theinertial force that attenuates the transverse vibration at the top andbottom of the passenger car, and the inertial force is applied to thepassenger car. As a result, the transverse vibration at the top andbottom of the passenger car is reduced, and comfortableness of riding inthe passenger car is improved.

According to the elevator vibration control apparatus of the seventhembodiment that is based on the fifth or sixth embodiment, the twodisplacement detectors horizontally face each other, and the operationdevice calculates a weighted average of displacement signals from thetwo displacement detectors and provides the operation unit with theweighted average, to more correctly detect a transverse displacement ofthe passenger car. The detected displacement is used to let thetranslation mechanism correctly control the movement of the weight. As aresult, the transverse vibration of the passenger car is effectivelyattenuated, and comfortableness of riding in the passenger car isimproved.

According to the elevator vibration control apparatus of the eighthembodiment that is based on any one of fifth through seventhembodiments, the noncontact-type displacement detector is used to detecta transverse displacement of the passenger car relative to the guiderail.

According to the elevator vibration control apparatus of the inventionof claim 9 that is based on any one of fifth through seventh embodiment,the contact-type displacement detector is attached to the passenger car,to detect a transverse displacement when the guide rollers roll alongthe guide rails, and provide a signal representing a transversedisplacement of the passenger car.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic view showing a first embodiment of the invention;

FIG. 2 is a schematic view showing an actuator of the above embodiment;

FIG. 3 is a sectional view showing the structure of a piezoelectricelement of the actuator of the above embodiment;

FIG. 4 is a block diagram showing a circuit of the above embodiment;

FIGS. 5A-B Are a view explaining a vibration damping action of the aboveembodiment;

FIG. 6 is a schematic view showing a fourth embodiment of the invention;

FIG. 7 is a block diagram showing a circuit of the above embodiment;

FIG. 8 is a schematic view showing a third embodiment of the invention;

FIG. 9 is a schematic view showing a fifth embodiment of the invention;

FIG. 10 is an enlarged view showing the structure of a displacementsensor of the above embodiment;

FIG. 11 is a block diagram showing a circuit according to a sixthembodiment of the invention;

FIG. 12 is a schematic view showing a seventh embodiment of theinvention;

FIG. 13 is a schematic view showing an eighth embodiment of theinvention;

FIG. 14 is a schematic view showing an embodiment of the aboveinvention;

FIG. 15 is a schematic view showing a ninth embodiment of the invention;

FIG. 16 is a schematic view showing a prior art; and

FIG. 17 is an enlarged view showing a guide unit of the prior art.

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of this invention will be explained in detail with referenceto the drawings. FIG. 1 shows a vibration control apparatus for a firstelevator according to an embodiment of the invention. Many parts of thisembodiment are the same as those of the prior art of FIGS. 16 and 17.These parts are represented with like reference marks and are notexplained again. This embodiment is characterized by a guide unit 7whose details are shown in FIG. 2, a controller 12 for controlling theguide unit 7, and an acceleration sensor 11 for detecting vibration of apassenger car 4.

Four guide units 7 are arranged at left and right corners on the top andbottom of the passenger car, to guide a passenger car frame 5 upwardlyor downwardly along a pair of guide rails 2 vertically installed in anelevator passage 1 of a building. A passenger car chamber 6 is supportedby the passenger car frame 5 through floor support frames 9 and rubberdampers 10. The passenger car 4 is hoisted up or down by hoist cables 3.The guide rails 2 involve curves and level differences at joints due toinstallation errors, etc. When the passenger car 4 passes over thecurves and level differences of the guide rails, it is forciblydisplaced to cause transverse vibration. The acceleration sensor 11attached to the passenger car chamber 6 detects the transversevibration. The controller 12 calculates an operation quantity necessaryfor attenuating the transverse vibration. According to the calculatedoperation quantity, a piezoelectric element 8f serving as an actuator ofthe guide unit 7 of FIG. 2 and a presser spring 8e apply force to thepassenger car 4.

The guide unit 7 of FIG. 2 consists of a guide base 8a fixed to thepassenger car frame 5, a lever 8b rotatably attached to the guide base,a guide roller 8c rotatably attached to the other end of the lever 8b, arod 8d having an end fixed to the guide base 8a, the presser spring 8e,and the piezoelectric element 8f, i.e., the actuator. The presser springand piezoelectric element are arranged between the rod 8d and the lever8b, to suppress a displacement of the guide roller 8c. The guide roller8c rolls along the side and end faces of the guide rail 2.

As shown in FIG. 3, the piezoelectric element 8f, i.e., the actuatorconsists of laminated plate elements 21a. Each of the elements 21aproduces a small displacement of about 0.1 mm, but the laminatedstructure as a whole provides a large displacement. To enlarge adisplacement of the piezoelectric element 8f, the lever 8b isinterposed. This arrangement transfers a sufficient displacement to thepassenger car 4.

FIG. 4 shows an electric control system. An adder 22 provides adeviation of an acceleration signal of the acceleration sensor 11 from areference acceleration signal, i.e., a target acceleration signal. Thedeviation is supplied to the controller 12, which calculates a requireddisplacement and sends a voltage signal corresponding to the requireddisplacement to the piezoelectric element 8f. The piezoelectric element8f carries out a piezoelectric action to convert the input voltage intoa displacement, which is enlarged by the presser spring 8e and given tothe lever 8b. The lever 8b displaces the guide roller 8c accordingly.

The operation of the elevator vibration control apparatus of the aboveconfiguration will be explained. Level differences at the joints of andcurves in the guide rails 2 vibrate the passenger car 4. Theacceleration sensor 11 on the passenger car 4 provides a signalrepresenting the vibration. The signal is processed by the controller12, which provides the piezoelectric element 8f, i.e., the actuator witha voltage corresponding to a required displacement. The piezoelectricelement 8f converts the voltage into a displacement, which is given tothe presser spring 8e and is enlarged by the lever 8b. As a result,force to cancel the acceleration of the passenger car 4 is applied tothe passenger car 4. Consequently, the acceleration of the passenger car4 is zeroed, to thereby stop the passenger car 4 from transverselyvibrating.

When the elevator is stopped at a requested floor, the displacement ofthe piezoelectric element 8f, i.e., the actuator is returned to areference value, and then, the elevator is hoisted up or down. If theactuator keeps the displacement, no damping action will be achieved.

In this way, the elevator vibration control apparatus of this embodimentactively suppresses transverse vibration of the passenger car, toimprove comfortableness of the elevator. The acceleration sensor iseasily attached to the passenger car. The piezoelectric element, i.e.,the actuator is light, and therefore, the vibration control apparatus ofthis invention is easily added to a conventional elevator.

The elevator vibration control apparatus according to the invention isnot limited to the above embodiment. The above embodiment achieves adamping action against transverse acceleration as shown in FIG. 5A. Itis possible to attach one or more angular acceleration sensors to thepassenger car. The controller processes angular acceleration detected bythe angular acceleration sensors and provides a voltage signal todisplace the piezoelectric element, i.e., the actuator to cancel thedetected angular acceleration. This arrangement is capable of dampingrotational vibration of the passenger car as shown in FIG. 5B, tofurther improve comfortableness of the elevator.

The first embodiment of the invention arranges the actuator 8f only forthe guide unit 7 on the top of the passenger car 4. This embodiment doesnot limit the invention. A second embodiment according to the inventionarranges the piezoelectric element 8f, i.e., the actuator of thevibration control apparatus on each of the top and bottom of thepassenger car 4. The acceleration sensor 11 is also arranged at a properlocation on each of the top and bottom of the passenger car 4. Accordingto acceleration signals from the top and bottom acceleration sensors 11,the controllers 12 control voltages applied to the top and bottompiezoelectric elements 8f.

In this embodiment, the top and bottom acceleration sensors 11 detecttransverse vibration at the top and bottom of the passenger car 4.According to the detected vibration, the top and bottom controllers 12control displacements of the top and bottom piezoelectric elements 8f,to cancel the vibration acceleration at the top and bottom of thepassenger car. Namely, the controllers 12 send control signals to thetop and bottom piezoelectric elements 8f, i.e., the actuators, whichdisplace the top and bottom of the passenger car 4. In this way,transverse vibration of the passenger car 4 is more effectively reduced,and comfortableness of riding in the passenger car is improved.

A vibration control apparatus for an elevator according to a fourthembodiment of the invention will be explained with reference to FIGS. 6and 7. Each of the top and bottom of a passenger car 4 is provided withan actuator 16 including a servomotor 13, a translation mechanism 14,and a weight 15 linearly moved thereby, a vibration sensor 17 arrangedon the passenger car 4 in the vicinity of the actuator 16, a controller18 for calculating a driving quantity of the servomotor 13 according tovibration detected by the vibration sensor 17, to produce inertial forceto cancel the detected vibration, and a driver 19 for driving theservomotor 13. Numeral 20 is a position sensor for the weight 15.

In the elevator vibration control apparatus of this arrangement, thevibration sensors 17 detect transverse vibration of the passenger car 4caused by level differences of joints of and curves in the guide railsin the elevator passage of FIG. 1 and provide acceleration signalsrepresenting the detected vibration. A deviation of each of theacceleration signals from a reference acceleration signal, i.e., atarget acceleration signal is found, and according to the deviations,the controllers 18 calculate driving quantities of the servomotors toproduce opposing inertial force to cancel the transverse vibration.According to the calculated driving quantities, the drivers 19 drive theservomotors 13 in a forward or reverse direction, to let the translationmechanisms 14 linearly move the weights 15 through threads in adirection to cancel the transverse vibration. As a result, thetransverse vibration of the passenger car 4 is suppressed.

As shown in FIGS. 5A-B, the passenger car 4 causes translationalvibration and rotational vibration. The translational vibration of FIG.5A is suppressed when the top and bottom controllers 18 move the weights15 in the same direction. When the passenger car 4 causes the rotationalvibration of FIG. 5B, the top and bottom vibration sensors 17 detectvibrations of opposite phases. As a result, the top and bottomcontrollers 18 move the weights 15 in opposite directions, to suppressthe rotational vibration.

In this way, the elevator vibration control apparatus of this embodimentsuppresses transverse vibration of the passenger car of the elevator bymoving the weights in a direction to cancel the transverse vibration.Then, the weights produce inertial force to suppress the transversevibration, thereby improving comfortableness of riding in the elevator.

FIG. 8 shows a third embodiment of the invention of. Unlike thepreceding embodiment, this embodiment arranges an elevator vibrationcontrol apparatus only on the bottom or top of a passenger car 4.Arranging the vibration control apparatus on the bottom of the passengercar 4 is advantageous because the bottom of the passenger car 4 has alarge installation space and because operation noise of the vibrationcontrol apparatus is far from and insensitive to the ears of persons inthe passenger car 4.

An elevator vibration control apparatus according to fifth and seventhembodiments will be explained with reference to FIGS. 9 to 11. Manyparts of the elevator vibration control apparatus of this embodiment arethe same as those of the prior art of FIGS. 16 and 17. These parts arerepresented with like reference marks and are not explained again. Thesame parts as those of the embodiments of FIGS. 1 to 8 are alsorepresented with like reference marks and are not explained again.

The elevator vibration control apparatus of this embodiment provides thetop of a passenger car 4 with a servomotor 13, a translation mechanism14 driven by the servomotor, for converting rotational motion intolinear motion, a weight 15 to be linearly moved by the translationmechanism 14, and a displacement sensor 21 attached to each of left andright guide units 7. An enlarged view of the guide unit 7 is shown inFIG. 10. The guide unit 7 has a guide base 8a, a rocking lever 8b havingone end attached to the guide base 8a, a guide roller 8c rotatablyattached to the other end of the lever 8b, to roll along a guide rail 2installed in an elevator passage 1, a rod 8d having one end fixed to theguide base 8a, and a spring 8e attached to the rod 8d. The spring 8epresses the lever 8b against the guide rail 2, so that the guide roller8c may be pressed against the guide rail 2 and roll along the guide rail2.

The displacement sensor 21 is arranged between the guide base 8a and thelever 8b of each of the left and right guide units 8, to detect adisplacement of the lever 8b relative to the passenger car 4. Thedisplacement sensor 21 may be a potentiometer to provide a voltagesignal corresponding to a displacement of a contact from the lever 8b.The voltage signal is used as a displacement signal.

FIG. 11 shows an arrangement of the elevator vibration control apparatusof this embodiment. The apparatus includes an A/D converter 22 forconverting displacement signals from the left and right displacementsensors 21 into digital signals, an operation unit 23 for calculating aweighted average of left and right displacements according to thedisplacement digital signals provided by the A/D converter 22, theweighted average being used to find a shift of the weight 15 toattenuate transverse vibration of the passenger car 4 as well as adriving quantity of the servomotor 13 corresponding to the shift of theweight, a D/A converter 24 for converting the servomotor driving digitalsignal into an analog signal, and a servo driver 25 for driving theservomotor 13 according to the signal provided by the D/A converter 24.

When the elevator is stopped at a requested floor, the weight 15 of thetranslation mechanism 14 must be returned to an initial position. Forthis purpose, the translation mechanism 14 has a sensor 20 for detectingthe position of the weight 15. A signal from the position sensor 20 issupplied to the operation unit 23 through the A/D converter 22. Theoperation unit 23 calculates a positional deviation of the weight 15,finds out a driving quantity of the servomotor 13 to return the weightto the initial position, and provides the driving quantity to the servodriver 25.

An operation of the elevator vibration control apparatus of the abovearrangement will be explained. When the passenger car 4 of the elevatoris hoisted up or down along the guide rails 2, curves in the guide rails2 and level differences at joints of the guide rails 2 may vibrate thepassenger car 4. Due to a displacement relative to the guide rails 2,the lever 8b and guide roller 8c pushed by the spring 8e of the guideunit 7 are transversely displaced with respect to the guide base 8a. Therelative displacement is detected by each of the displacement sensors 21and is supplied to the operation unit 23 through the A/D converter 22.

The operation unit 23 calculates a weighted average of the displacementsignals from the left and right displacement sensors 21. When the rightdisplacement sensor 21 detects a displacement Xr(t) and the leftdisplacement sensor 21 detects a displacement Xl(t), a displacement X(t)of the passenger car 4 is calculated as follows:

    X(t)=(Xr(t)+Xl(t))/2                                       (1)

With the mass of the weight 15 of the translation mechanism 14 being M,a lead (a distance moved by the weight 15 when the shaft of thetranslation mechanism turns once) being γ, and a rotational anglevelocity of the servomotor 13 being Ω(t), the operation unit 23calculates inertial force F(t) to be produced by the weight 15 asfollows:

    F(t)=γ/2π·M·dΩ(t)/dt      (2)

When the operation unit 23 and servo driver 25 provide the angularvelocity Ω(t) of the servomotor 13 in proportion to the displacementX(t), the following is established:

    Ω(t)=k·X(t)                                 (3)

Then, the inertial force F(t) is as follows:

    F(t)=γ/2π·kM·dX(t)/dt           (4)

Namely, the inertial force is determined by the displacement X(t). Here,k is a proportional gain.

According to the expression (4), the inertial force F(t) is provided bya temporal differentiation of the displacement X(t), i.e., in proportionto the velocity. The operation unit 23 calculates the displacement X(t),temporally differentiates the displacement X(t), multiplies the resultby the proportional gain k that is experimentally obtained, and providesthe servo driver 25 with an angular velocity instruction Ω(t). As aresult, the weight 15 is moved to produce the inertial forcecorresponding to transverse vibration of the passenger car 4, to therebyeffectively attenuate the transverse vibration of the passenger car 4.

The invention of the fifth embodiment has other variations. Thevibration control apparatus mentioned above may be arranged only on thebottom of the passenger car 4. The above embodiment calculates aweighted average of signals from the left and right displacement sensors21. Instead, the displacement sensor may be arranged on one side, or atthe center.

A sixth embodiment according to the invention will be explained withreference to FIG. 12. This embodiment arranges the vibration controlapparatus of FIGS. 9 and 10 on each of the top and bottom of a passengercar 4. Namely, this embodiment provides each of the top and bottom ofthe passenger car 4 with a servomotor 13, a translation mechanism 14driven by the servomotor, for converting rotational motion into linearmotion, a weight 15 to be linearly moved by the translation mechanism14, and a displacement sensor 21 provided for each of left and rightguide units 7.

A circuit of each of the top and bottom vibration control apparatuses isthe same as that of FIG. 11. Namely, each of the vibration controlapparatuses has an A/D converter 22 for converting displacement signalsfrom the left and right displacement sensors 21 into digital signals, anoperation unit 23 for calculating a weighted average of left and rightdisplacements according to the digital signals, the weighted averagebeing used to find a shift of the weight 15 to attenuate transversevibration of the passenger car 4 as well as a driving quantity of theservomotor 13 corresponding to the shift of the weight, a D/A converter24 for converting a servomotor driving digital instruction signalprovided by the operation unit 23 into an analog signal, and a servodriver 25 for driving the servomotor 13 according to the signal from theD/A converter 24.

According to the embodiment of FIG. 12, the top vibration controlapparatus attenuates vibration at the top of the passenger car 4, andthe bottom vibration control apparatus attenuates vibration at thebottom of the passenger car 4. In this way, this embodiment separatelyattenuates transverse vibration at the top and bottom of the passengercar 4, to effectively reduce transverse vibration of the passenger car 4and more effectively improve comfortableness of riding in the passengercar.

FIG. 13 shows an eighth embodiment of an elevator vibration controlapparatus. This embodiment provides a displacement sensor adoptable forthe elevator vibration control apparatuses of the inventions of thefifth through seventh embodiments. The displacement sensor of FIG. 13 isa distance sensor 21a for detecting a displacement of a passenger car 4.The distance sensor 21a may be an ultrasonic sensor or a photoelectricsensor attached to a guide base 8a fixed to the passenger car 4. Thedistance sensor 21a detects a distance up to a lever 8b that is pushedby a spring 8e. The spring 8e presses a guide roller 8c against a guiderail 2 so that the guide roller 8c rolls along the guide rail 2. Asignal representing the detected distance is used to calculate atransverse displacement of the passenger car 4.

The distance signal from the distance sensor 21a is supplied to theoperation unit 23 of FIG. 11, which temporally differentiates the signalto find a displacement X(t) of the passenger car 4. According to thedisplacement X(t) and the expressions (1) to (4) mentioned above, anangular velocity Ω(t) of the servomotor 13 is obtained to control therotation of the servomotor 13. Consequently, the weight 15 producesinertial force F(t) to attenuate transverse vibration of the passengercar 4 and improve comfortableness of riding in the passenger car.

FIG. 14 shows another displacement sensor according to an eighthembodiment of the invention. The displacement sensor of this embodimentis a noncontact-type distance sensor 21b attached to a guide base 8a ofa guide unit 7, to detect a transverse displacement of a passenger car4. The distance sensor 21b detects a distance up to a guide rail 2 andprovides a 10 distance signal, which is temporally differentiated tofind a displacement of the passenger car 4.

Similar to the embodiment of FIG. 13, the distance sensor 21b of thisembodiment provides the operation unit 23 of the circuit of FIG. 11 withthe distance signal. The operation unit 23 temporally differentiates thesignal, to find a displacement X(t) of the passenger car 4. Thedisplacement X(t) is used to calculate an angular velocity Ω(t) of theservomotor 13 according to the expressions (1) to (4). The rotation ofthe servomotor 13 is controlled accordingly, to attenuate transversevibration of the passenger car 4 by inertial force F(t) of the weight15. As a result, comfortableness of the elevator is improved.

FIG. 15 shows a ninth embodiment of the invention of. A roller 21c ismovably attached to a passenger car 4. The roller 21c is pressed againsta guide rail 2 by a spring 21d. The roller 21c is used to detect adisplacement of the passenger car 4 according to a change in thedistance between the passenger car 4 and the guide rail 2. In responseto a displacement of the roller 21c, a displacement sensor 21e such as apotentiometer detects the displacement. The displacement sensor 21eprovides a displacement signal, which is sent to the operation unit 23of FIG. 11. Similar to the preceding embodiments, this embodimentcontrols the rotation of the servomotor 13 to let the weight 15 produceinertial force F(t) to attenuate transverse vibration of the passengercar 4, to improve comfortableness of the passenger car.

Industrial Applicability

As explained above, the invention of the first embodiment attaches anacceleration sensor to a passenger car of an elevator. According to avalue detected by the acceleration sensor, a piezoelectric elementserving as an actuator attached to a guide roller is displaced to applyforce to the passenger car in a direction to cancel the detectedacceleration. In this way, the invention suppresses transverse vibrationof the passenger car by forcibly displacing the passenger car in anopposite phase, to thereby improve comfortableness of the elevator.

The invention of the second embodiment provides each of the top andbottom of a passenger car of an elevator with a vibration sensor todetect transverse vibration at the top and bottom of the passenger car.Top and bottom controllers calculate operation quantities of top andbottom actuators, to cancel vibration acceleration at the top and bottomof the passenger car. The calculated operation quantities are sent tothe top and bottom actuators to displace multilayer piezoelectricelements of the top and bottom actuators. As a result, the top andbottom of the passenger car are displaced in a direction to attenuatethe transverse vibration, to suppress force applied to the passengercar. This arrangement more effectively reduces transverse vibration ofthe passenger car and improves comfortableness of riding in thepassenger car.

The invention of the third embodiment employs a vibration sensor fordetecting vibration of a passenger car of an elevator and a controllerfor processing a signal from the vibration sensor. The controller drivesa servomotor, which drives a translation mechanism. The translationmechanism linearly moves a weight so that the weight produces inertialforce in a direction to cancel the vibration of the passenger car. Theinertial force is applied to the passenger car, to attenuate thevibration of the passenger car and improve comfortableness of riding inthe passenger car.

The invention of the fourth embodiment arranges a vibration sensor oneach of the top and bottom of a passenger car of an elevator. Thevibration sensors detect transverse vibration at the top and bottom ofthe passenger car. Signals from the top and bottom vibration sensors areprocessed by top and bottom controllers, which drive top and bottomservomotors. These servomotors drive top and bottom translationmechanisms accordingly, to linearly horizontally move top and bottomweights to produce inertial force in directions to attenuate thetransverse vibration at the top and bottom of the passenger car. Theinertial force is applied to the top and bottom of the passenger car, toattenuate the transverse vibration at the top and bottom of thepassenger car, to thereby more effectively improve comfortableness ofriding in the passenger car.

The invention of the fifth embodiment detects a displacement due totransverse vibration of a passenger car of an elevator. According to asignal representing the detected displacement, a driving quantity of aservomotor is calculated to let a translation mechanism horizontallymove a weight for a distance to attenuate the transverse vibration ofthe passenger car due to a transverse displacement of a guide roller.According to the calculated driving quantity, the servomotor is drivento activate the translation mechanism, which moves the weight. Theweight produces inertial force to attenuate the transverse vibration ofthe passenger car. Consequently, the transverse vibration of thepassenger car is reduced to improve comfortableness of riding in thepassenger car.

The invention of the sixth embodiment detects displacements at the topand bottom of a passenger car of an elevator, and according to signalsrepresenting the detected displacements, calculates driving quantitiesof top and bottom servomotors. These servomotors drive top and bottomtranslation mechanisms, which horizontally move top and bottom weightsfor distances to attenuate the transverse vibration at the top andbottom of the passenger car due to transverse displacements of guiderollers. In this way, the top and bottom servomotors are drivenaccording to the calculated driving quantities to let the top and bottomtranslation mechanisms move the wights to apply inertial force to thepassenger car, to thereby attenuate the transverse vibration at the topand bottom of the passenger car. As a result, the transverse vibrationat the top and bottom of the passenger car are reduced to improvecomfortableness of riding in the passenger car.

The invention of the seventh embodiment arranges two displacementdetectors on left and right sides, respectively, on each or both of thetop and bottom of a passenger car of an elevator. The left and rightdisplacement detectors face each other. Displacement signals from thetwo displacement detectors are weighted and averaged into a normaldisplacement. Accordingly, a displacement at the top or bottom of thepassenger car is correctly detected, and a movement of a weightcorresponding to the displacement can be correctly calculated toeffectively reduce transverse vibration of the passenger car and improvecomfortableness of riding in the passenger car.

The invention of the eighth embodiment is based on the elevatorvibration control apparatus of one of the fifth through seventhembodiments and employs a noncontact-type displacement detector fordetecting a transverse displacement of a passenger car of an elevatorrelative to a guide rail.

The invention of the ninth embodiment is based on the elevator vibrationcontrol apparatus of one of claims 5 to 7 and employs a contact-typedisplacement detector attached to a passenger car of an elevator, todetect a transverse displacement of a guide roller when the guide rollerrolls along a guide rail, to provide a signal representing a transversedisplacement of the passenger car.

We claim:
 1. In an elevator having guide rails installed in an elevator passage and a guide unit arranged on the top and bottom of a passenger car of the elevator, the guide unit having a rocking lever attached to the passenger car, a guide roller rotatably attached to the lever, and a spring for pressing the guide roller against the guide rail so that the guide roller may roll along the guide rail, a vibration control apparatus comprising a servomotor arranged on one of the top and bottom of the passenger car of the elevator, a translation mechanism driven by said servomotor, for converting rotational motion into linear motion, a weight to be linearly horizontally moved by said translation mechanism, a vibration sensor for detecting transverse vibration of the passenger car, and a controller for driving said servomotor according to a signal from said vibration sensor, to let said weight linearly horizontally move to produce inertial force in a direction to cancel the transverse vibration of the passenger car.
 2. The elevator vibration control apparatus as set forth in claim 1, wherein each of the top and bottom of the passenger car of the elevator is provided with a servomotor, a translation mechanism driven by the servomotor, for converting rotational motion into linear motion, a weight to be linearly horizontally moved by the translation mechanism, a vibration sensor for detecting vibration of the passenger car, and a controller for driving the servomotor according to a signal from the vibration sensor, to let the weight linearly horizontally move to produce inertial force in a direction to cancel the transverse vibration of the passenger car.
 3. In an elevator having guide rails installed in an elevator passage and a guide unit arranged on the top and bottom of a passenger car of the elevator, the guide unit having a rocking lever attached to the passenger car, a guide roller rotatably attached to the lever, and a spring for pressing the guide roller against the guide rail so that the guide roller may roll along the guide rail, a vibration control apparatus comprising a weight arranged on one of the top and bottom of the passenger car of the elevator, a translation mechanism for linearly horizontally move said weight, a servomotor for driving said translation mechanism, displacement detection means attached to the guide unit, for detecting a transverse displacement of the guide roller, an operation unit for calculating a driving quantity of said servomotor according to a signal from said displacement detection means, to let said translation mechanism horizontally move said weight for a distance to attenuate transverse vibration of the passenger car due to the transverse displacement of the guide roller, and a controller for driving said servomotor according to the driving quantity calculated by said operation unit.
 4. The elevator vibration control apparatus as set forth in claim 3, wherein each of the top and bottom of the passenger car of the elevator is provided with a weight, a translation mechanism for linearly horizontally move the weight, a servomotor for driving the translation mechanism, displacement detection means attached to the guide unit, for detecting a transverse displacement of the guide roller, an operation unit for calculating a driving quantity of the servomotor according to a signal from the displacement detection means, to let the translation mechanism horizontally move the weight for a distance to attenuate transverse vibration of the passenger car due to the transverse displacement of the guide roller, and a controller for driving the servomotor according to the driving quantity calculated by the operation unit.
 5. The elevator vibration control apparatus as set forth in claim 3, wherein said displacement detection means comprises two displacement sensors which are arranged on left and right sides of the passenger car, and said operation unit calculates a weighted average of displacement signals from the two displacement sensors and provides the weighted average.
 6. The elevator vibration control apparatus as set forth in claim 3, wherein said displacement detection means is a noncontact-type detector for detecting a transverse displacement of the passenger car relative to the guide rail.
 7. The elevator vibration control apparatus as set forth in claim, 3 wherein said displacement detection means is a contact-type displacement detector attached to the passenger car, to detect a transverse displacement of the guide roller when the guide roller rolls along the guide rail and provide a signal representing a transverse displacement of the passenger car.
 8. The elevator vibration control apparatus as set forth in claim 4, wherein said displacement detection means comprises two displacement sensors which are arranged on left and right sides of the passenger car, and said operation unit calculates a weighted average of displacement signals from the two displacement detection sensors and provides the weighted average.
 9. The elevator vibration control apparatus as set forth in claim 6, wherein said displacement detection means is a noncontact-type displacement detector for detecting a transverse displacement of the passenger car relative to the guide rail.
 10. The elevator vibration control apparatus as set forth in claim 5, wherein said displacement detection sensors are noncontact-type sensors for detecting a transverse displacement of the passenger car relative to the guide rail.
 11. The elevator vibration control apparatus as set forth ir claim 4, wherein said displacement detection means is a contact-type displacement detector attached to the passenger car, to detect a transverse displacement of the guide roller when the guide roller rolls along the guide rail and provide a signal representing a transverse displacement of the passenger car.
 12. The elevator vibration control apparatus as set forth in claim 5, wherein said displacement detection sensors are contact-type sensors attached to the passenger car, to detect a transverse displacement of the guide roller when the guide roller rolls along the guide rail and provide a signal representing a transverse displacement of the passenger car. 